The invention relates to a device for measuring and recording the location, the attitude and/or the change of location or, respectively, attitude of a rigid body in space, employing a field generator, preferably a magnetic field generator, arranged directly at or at a distance from the body, said generator generating a defined irregular field, with pickups independent of the body arranged at a distance from the field generator, said pickups having field flux-dependent sensor elements for sensing the field flux or, respectively, a change of field flux during a measurement, and an electronic device for receiving and evaluating electric signals arising due to a field flux or, respectively, a change of field flux.
A device of this type is proposed in the German patent application No. P 28 14 551 in which a V-shaped permanent magnet is provided as the field generator and six bar-shaped magnetic flux pickups are provided for sensing the field flux or, respectively, a change of field flux. The magnetic flux pickups are arranged by pairs in three planes that are perpendicular to one another; thus, three surfaces which are perpendicular to one another are formed by means of their arrangement. The entire pickup system is arranged so as to be laterally offset from the patient. Because of the asymmetrical arrangement of the system, nonlinear signals derive which, in order to be evaluatable at all, must be linearized in an electronic manner with a corresponding circuit outlay. Operation of the device, moreover is too complicated and requires too much time for the physician in view of the alignment of the magnetic field pickups on the head of the patient and with respect to the null balance of the electronics. Moreover, the balance of the linearization amplifier is problematic because an inprecision caused, for example, by means of a temperature drift, has an effect on the sensitivity and, thus, on the reproduceability of the signals obtained because of the nonlinear characteristic curve of the sensor elements (Hall generators as a rule) being employed, which the pickups contain.